The following relates to compression devices, and more particularly relates to a novel and improved hand-held universal compression tool for crimping fittings of different lengths and diameters into sealed engagement with cables, such as, for example, coaxial cables employed in the cable TV industry.
Hand-held compression tools have been devised for crimping a connector onto the end of a coaxial cable and which are characterized in particular by being capable of reducing the diameter of the fitting into a generally circular configuration in response to an axially directed force to the fitting. Representative of these inventions are U.S. Pat. No. 5,392,508 for AXIAL DEFORMATION CRIMPING TOOL and U.S. Pat. No. 6,293,004 for LENGTHWISE COMPLIANT CRIMPING TOOL, both of said patents being owned by the assignee of this invention and incorporated by reference herein, the latter being characterized in particular by having a spring-loaded chuck on the end of a plunger which is axially advanced by a lever arm toward and away from an end stop into which a coaxial cable end and connector have been inserted. Movement of the plunger toward the end stop will force a crimping ring on the connector to radially contract the connector into crimping engagement with the cable end, and the spring-loaded chuck will compensate for differences in length of the fittings.
In U.S. Pat. No. 6,293,004, utilization of a preassembled crimping ring on the connector obviates utilization of a special die portion of the type disclosed in my U.S. Pat. No. 5,392,508. Nevertheless, there are numerous applications where utilization of a die portion mounted on the body of the tool is preferred over the utilization of a preassembled crimping ring. For example, the die portion eliminates the crimping ring and exerts more direct control over shaping of the fitting or sleeve into sealed engagement with the cable end. In the past, however, when the die portions have been mounted on the body of the tool they are difficult to open when the fitting becomes jammed; also the ability of the die halves to resist misalignment when subjected to crimping forces; and the ability of the tool to be self-adjusting for wear tolerances and other slight differences in size and length of each fitting or connector have presented problems in the field. Accordingly, there is an unmet need for a compression tool which will overcome the above and other problems associated with cable compression tools.
There is a further need for a universal compression tool capable of handling a wide range in sizes of coaxial cable connectors including the mini-coaxial cables, and which is adjustable to conform to variations in diameter and length of different cable fittings. In this relation, it is important to make the end of the plunger accessible to the user for the purpose of installing or removing an extension tip to make the necessary adjustment in length for the shorter cable fittings. Further, in the smaller size cables, it is important to compensate for the difference in diameter between standard cables and the smaller sized cables so that the tool embodiment herein described can crimp the fitting onto the cable without having to adjust the extent of radial and axial advancement of the die members.